TY - JOUR AU - Yu, T.-W. AU - Müller, R. AU - Müller, M. AU - Floss, H. G. TI - Mutational analysis and reconstituted expression of the biosynthetic genes involved in the formation of 3-amino-5-hydroxybenzoic acid : the starter unit of rifamycin biosynthesis in Amycolatopsis mediterranei S699 JO - The journal of biological chemistry VL - 276 SN - 0021-9258 CY - Bethesda, Md. PB - Soc. M1 - PreJuSER-33246 SP - 12546 - 12555 PY - 2001 N1 - Record converted from VDB: 12.11.2012 AB - To investigate a novel branch of the shikimate biosynthesis pathway operating in the formation of 3-amino-5-hydroxybenzoic acid (AHBA), the unique biosynthetic precursor of rifamycin and related ansamycins, a series of target-directed mutations and heterologous gene expressions were investigated in Amycolatopsis mediterranei and Streptomyces coelicolor. The genes involved in AHBA formation were inactivated individually, and the resulting mutants were further examined by incubating the cell-free extracts with known intermediates of the pathway and analyzing for AHBA formation. The rifL, -M, and -N genes were shown to be involved in the step(s) from either phosphoenolpyruvate/d-erythrose 4-phosphate or other precursors to 3,4-dideoxy-4-amino-d-arabino-heptulosonate 7-phosphate. The gene products of the rifH, -G, and -J genes resemble enzymes involved in the shikimate biosynthesis pathway (August, P. R., Tang, L., Yoon, Y. J., Ning, S., Müller, R., Yu, T.-W., Taylor, M., Hoffmann, D., Kim, C.-G., Zhang, X., Hutchinson, C. R., and Floss, H. G. (1998) Chem. Biol. 5, 69-79). Mutants of the rifH and -J genes produced rifamycin B at 1% and 10%, respectively, of the yields of the wild type; inactivation of the rifG gene did not affect rifamycin production significantly. Finally, coexpressing the rifG-N and -J genes in S. coelicolor YU105 under the control of the act promoter led to significant production of AHBA in the fermented cultures, confirming that seven of these genes are indeed necessary and sufficient for AHBA formation. The effects of deletion of individual genes from the heterologous expression cassette on AHBA formation duplicated the effects of the genomic rifG-N and -J mutations on rifamycin production, indicating that all these genes encode proteins with catalytic rather than regulatory functions in AHBA formation for rifamycin biosynthesis by A. mediterranei. KW - Actinomycetales: enzymology KW - Actinomycetales: genetics KW - Amino Acid Sequence KW - Aminobenzoic Acids: metabolism KW - Base Sequence KW - DNA Mutational Analysis: methods KW - DNA Primers KW - Genes, Bacterial KW - Genes, Regulator KW - Molecular Sequence Data KW - Multigene Family KW - Open Reading Frames KW - Plasmids KW - Promoter Regions, Genetic KW - Restriction Mapping KW - Rifabutin: metabolism KW - Rifamycins: biosynthesis KW - Aminobenzoic Acids (NLM Chemicals) KW - DNA Primers (NLM Chemicals) KW - Rifamycins (NLM Chemicals) KW - Rifabutin (NLM Chemicals) KW - 3-amino-5-hydroxybenzoic acid (NLM Chemicals) KW - J (WoSType) LB - PUB:(DE-HGF)16 C6 - pmid:11278540 UR - <Go to ISI:>//WOS:000168198600013 DO - DOI:10.1074/jbc.M009667200 UR - https://juser.fz-juelich.de/record/33246 ER -